Hi,
just to be clear, Intel Iris GPUs are the worst GPUs you can have for GPU rendering.
You are forced to go back to macOS Big Sur, since Apple has stoped to support them for GPU rendering from macOS Monterey.
They are very very slow, with few VRAM, and not fully supported, materials preview doesn't work!
Solutions:
1. invest in an eGPU box via Thunderbolt port + AMD Radeon Vega, Navi or Big Navi GPU.
This solution is quite expensive, and doesn't have future, Apple has stopped to support AMD GPU for rendering from Ventura.
2. Sell your Mac and switch to an used Mac with Apple Silicon M1/M2, or new M3, to be able to use latest OctaneX versions, identical to CUDA PC version, with very good performance.
ciao,
Beppe